The couple’s assets amounted to more than £4m, including a London flat bought by Lawrence for £650,000 before he met Gallagher and now valued at £2.4m, and a country cottage worth £822,000 that they bought together.

The judge ordered that Lawrence keep the flat and Gallagher be given the cottage plus a lump sum of £577,778 to reflect the difference in value of the properties. Lawrence appealed, arguing Gallagher had been given too big a share.

Reducing the lump sum to £350,000, Lord Justice Thorpe said: “I believe it would have been safer and more orthodox for the judge to have assessed the fair lump sum from the foundation that the respondent would have Pine Cottage and his pension share as the foundations of the award.

“Had she so approached the case I conclude that the lump sum would have been at a significantly lower figure.”

Lawrence’s solicitor, Sarah Higgins, partner at Charles Russell, says: “The casewas not about the principles of civil partnership, which are the same as on divorce, but about how to divide assets which were largely brought into the relationship by one party.

“The particular issue in this case was how much Mr Gallagher should receive in relation to the increase in value of a property owned by Peter Lawrence which shot up in value simply as a result of London property prices. The court decided that there was ‘no rationality’ to the original figure order by the judge last June and reduced the total award by about £320,000.”

Geraldine Morris, head of LexisPSL Family, says: “Lawrence v Gallagher has provided welcome clarification that the courts should approach financial provision in civil-partnership dissolution in exactly the same way as the courts approach financial provision on divorce.”